Combination Calculator
Compute nCr = n! ÷ (r!(n − r)!): how many unordered groups of r from n.
Calculator
Combination Calculator
Result
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Formula
nCr = n! ÷ (r! × (n − r)!)
Step-by-step
- 1
Enter n and r
n is the pool size, r is the group size.
- 2
Read the count
Unordered selections are shown.
Worked example
Example input: n: 10, r: 3
Result: 120
Related tools
- Permutation Calculator
Ordered arrangements.